Gibberellins (GAs) are essential phytohormones involved in numerous aspects of plant growth and development. Notably, the biochemistry and genetics of GA biosynthesis, which is associated with their endogenous regulation, have been largely resolved; however, a crucial unsolved question remains: the precise mechanism of the stepwise oxidation and subsequent removal of C-20 from C20 precursors, leading to bioactive C19 gibberellins, is still unresolved. To satisfy numerous requests from biologists, practical preparations of certain GAs that were isolated in miniscule quantities are highly demanded. Herein, we report the first practical syntheses of GA15 and GA24, the key C20 metabolites in gibberellin biosynthesis, from commercially available GA3. The protocols are robust and offer the capacity to produce GA24 and GA15 under gram scales in high overall yields and thus aid in further biological and related studies.

• MeSH
• gibereliny biosyntéza   chemická syntéza   MeSH
• hmotnostní spektrometrie s elektrosprejovou ionizací MeSH
• magnetická rezonanční spektroskopie s uhlíkem 13C MeSH
• protonová magnetická rezonanční spektroskopie MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• gibereliny MeSH

Potato represents the third most important crop worldwide and therefore to understand regulations of tuber onset is crucial from both theoretical and practical points of view. Photosynthesis and related carbohydrate status along with phytohormone balance belong to the essential factors in regulation of plant development including storage organ formation. In our work we used potato (Solanum tuberosum) cv. Lada and its spontaneously tuberizing mutant (ST plants) grown in vitro under low carbohydrate availability (non-inductive conditions). Small plant phenotype and readiness to tuberization of ST plants was, however, not accompanied by lower gibberellins levels, as determined by UHPLC-MS/MS. Therefore, we focused on the other inducing factor, carbohydrate status. Using HPLC, we followed changes in carbohydrate distribution under mixotrophic (2.5% sucrose in medium) and photoautotrophic conditions (no sucrose addition and higher gas and light availability) and observed changes in soluble carbohydrate allocation and starch deposition, favouring basal stem part in mutants. In addition, the determination of tuber-inducing marker gene expressions revealed increased levels of StSP6A in ST leaves. Collectively these data point towards the possibility of two parallel cross-talking pathways (carbohydrate - and gibberellin- dependent ones) with the power of both to outcompete the other one when its signal is for some reason extraordinary strong.

• Klíčová slova
• Carbohydrate distribution, Gibberellin, Photoautotrophic cultivation, Potato, Tuberization,
• MeSH
• geneticky modifikované rostliny genetika   metabolismus   MeSH
• gibereliny metabolismus   MeSH
• hlízy rostlin genetika   metabolismus   MeSH
• metabolismus sacharidů genetika   fyziologie   MeSH
• regulace genové exprese u rostlin genetika   fyziologie   MeSH
• rostlinné proteiny genetika   metabolismus   MeSH
• Solanum tuberosum genetika   metabolismus   MeSH
• tandemová hmotnostní spektrometrie MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• gibereliny MeSH
• rostlinné proteiny MeSH

We studied the effect of reducing the levels of the mitochondrial electron carrier cytochrome c (CYTc) in Arabidopsis thaliana. Plants with CYTc deficiency have delayed growth and development, and reach flowering several days later than the wild-type but with the same number of leaves. CYTc-deficient plants accumulate starch and glucose during the day, and contain lower levels of active gibberellins (GA) and higher levels of DELLA proteins, involved in GA signaling. GA treatment abolishes the developmental delay and reduces glucose accumulation in CYTc-deficient plants, which also show a lower raise in ATP levels in response to glucose. Treatment of wild-type plants with inhibitors of mitochondrial energy production limits plant growth and increases the levels of DELLA proteins, thus mimicking the effects of CYTc deficiency. In addition, an increase in the amount of CYTc decreases DELLA protein levels and expedites growth, and this depends on active GA synthesis. We conclude that CYTc levels impinge on the activity of the GA pathway, most likely through changes in mitochondrial energy production. In this way, hormone-dependent growth would be coupled to the activity of components of the mitochondrial respiratory chain.

• Klíčová slova
• Arabidopsis thaliana, DELLA protein, cytochrome c, gibberellin, mitochondrion,
• MeSH
• Arabidopsis růst a vývoj   metabolismus   MeSH
• cytochromy c nedostatek   metabolismus   fyziologie   MeSH
• energetický metabolismus MeSH
• gibereliny metabolismus   fyziologie   MeSH
• glukosa metabolismus   MeSH
• homeostáza MeSH
• mitochondrie metabolismus   MeSH
• proteiny huseníčku metabolismus   MeSH
• regulace genové exprese u rostlin MeSH
• škrob metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• cytochromy c MeSH
• GAI protein, Arabidopsis MeSH Prohlížeč
• gibereliny MeSH
• glukosa MeSH
• proteiny huseníčku MeSH
• škrob MeSH

BACKGROUND: Bread wheat (Triticum aestivum) is a major source of nutrition globally, but yields can be seriously compromised by water limitation. Redistribution of growth between shoots and roots is a common response to drought, promoting plant survival, but reducing yield. Gibberellins (GAs) are necessary for shoot and root elongation, but roots maintain growth at lower GA concentrations compared with shoots, making GA a suitable hormone for mediating this growth redistribution. In this study, the effect of progressive drought on GA content was determined in the base of the 4th leaf and root tips of wheat seedlings, containing the growing regions, as well as in the remaining leaf and root tissues. In addition, the contents of other selected hormones known to be involved in stress responses were determined. Transcriptome analysis was performed on equivalent tissues and drought-associated differential expression was determined for hormone-related genes. RESULTS: After 5 days of applying progressive drought to 10-day old seedlings, the length of leaf 4 was reduced by 31% compared with watered seedlings and this was associated with significant decreases in the concentrations of bioactive GA1 and GA4 in the leaf base, as well as of their catabolites and precursors. Root length was unaffected by drought, while GA concentrations were slightly, but significantly higher in the tips of droughted roots compared with watered plants. Transcripts for the GA-inactivating gene TaGA2ox4 were elevated in the droughted leaf, while those for several GA-biosynthesis genes were reduced by drought, but mainly in the non-growing region. In response to drought the concentrations of abscisic acid, cis-zeatin and its riboside increased in all tissues, indole-acetic acid was unchanged, while trans-zeatin and riboside, jasmonate and salicylic acid concentrations were reduced. CONCLUSIONS: Reduced leaf elongation and maintained root growth in wheat seedlings subjected to progressive drought were associated with attenuated and increased GA content, respectively, in the growing regions. Despite increased TaGA2ox4 expression, lower GA levels in the leaf base of droughted plants were due to reduced biosynthesis rather than increased catabolism. In contrast to GA, the other hormones analysed responded to drought similarly in the leaf and roots, indicating organ-specific differential regulation of GA metabolism in response to drought.

• Klíčová slova
• Drought, gene expression, gibberellins, plant hormones, wheat,
• MeSH
• gibereliny metabolismus   MeSH
• hormony metabolismus   MeSH
• kořeny rostlin metabolismus   MeSH
• listy rostlin metabolismus   MeSH
• období sucha MeSH
• pšenice * metabolismus   MeSH
• semenáček * metabolismus   MeSH
• voda metabolismus   MeSH
• zeatin MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• gibereliny MeSH
• hormony MeSH
• voda MeSH
• zeatin MeSH

A robust, reliable and high-throughput method for extraction and purification of gibberellins (GAs), a group of tetracyclic diterpenoid carboxylic acids that include endogenous growth hormones, from plant material was developed. The procedure consists of two solid-phase extraction steps (Oasis(®) MCX-HLB and Oasis(®) MAX) and gives selective enrichment and efficient clean-up of these compounds from complex plant extracts. The method was tested with plant extracts of Brassica napus and Arabidopsis thaliana, from which total recovery of internal standards of about 72% was achieved. A rapid baseline chromatographic separation of 20 non-derivatised GAs by ultra performance liquid chromatography is also presented where a reversed-phase chromatographic column Acquity CSH(®) and a mobile phase consisting of methanol and aqueous 10mM-ammonium formate is used. This method enables sensitive and precise quantitation of GAs by MS/MS in multiple-reaction monitoring mode (MRM) by a standard isotope dilution method. Optimal conditions, including final flow rate, desolvation temperature, desolvation gas flow, capillary and cone voltage for effective ionisation in the electrospray ion source were found. All studied GAs were determined as free acids giving dominant quasi-molecular ions of [M-H](-) with limits of detection ranging between 0.08 and 10 fmol and linear ranges over four orders of magnitude. Taking advantage of highly effective chromatographic separation of 20 GAs and very sensitive mass spectrometric detection, the presented bioanalytical method serves as a useful tool for plant biologists studying the physiological roles of these hormones in plant development.

• MeSH
• Arabidopsis chemie   MeSH
• Brassica napus chemie   MeSH
• chromatografie kapalinová metody   MeSH
• extrakce na pevné fázi MeSH
• gibereliny analýza   MeSH
• květy chemie   MeSH
• rostlinné extrakty analýza   MeSH
• tandemová hmotnostní spektrometrie metody   MeSH
• výhonky rostlin chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• gibereliny MeSH
• rostlinné extrakty MeSH

Gibberellins are produced by all vascular plants and several fungal and bacterial species that associate with plants as pathogens or symbionts. In the 60 years since the first experiments on the biosynthesis of gibberellic acid in the fungus Fusarium fujikuroi, research on gibberellin biosynthesis has advanced to provide detailed information on the pathways, biosynthetic enzymes and their genes in all three kingdoms, in which the production of the hormones evolved independently. Gibberellins function as hormones in plants, affecting growth and differentiation in organs in which their concentration is very tightly regulated. Current research in plants is focused particularly on the regulation of gibberellin biosynthesis and inactivation by developmental and environmental cues, and there is now considerable information on the molecular mechanisms involved in these processes. There have also been recent advances in understanding gibberellin transport and distribution and their relevance to plant development. This review describes our current understanding of gibberellin metabolism and its regulation, highlighting the more recent advances in this field.

• Klíčová slova
• Gibberellin metabolism,
• MeSH
• gibereliny metabolismus   MeSH
• metabolické sítě a dráhy MeSH
• regulátory růstu rostlin biosyntéza   metabolismus   MeSH
• rostliny metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• gibberellic acid MeSH Prohlížeč
• gibereliny MeSH
• regulátory růstu rostlin MeSH

• Klíčová slova
• ASCOMYCETES *, EXPERIMENTAL LAB STUDY *, GIBBERELLINS *, METABOLISM *, PHARMACOLOGY *, SOY BEANS *,
• MeSH
• Ascomycota * MeSH
• farmakologie * MeSH
• Fusarium * MeSH
• Gibberella * MeSH
• gibereliny * MeSH
• Glycine max * MeSH
• metabolismus * MeSH
• výzkum * MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• gibberellic acid MeSH Prohlížeč
• gibereliny * MeSH

• Klíčová slova
• BODY WEIGHT *, GIBBERELLINS *,
• MeSH
• gibereliny * MeSH
• hmotnostní přírůstek * MeSH
• morčata MeSH
• tělesná hmotnost * MeSH
• tělesné váhy a míry * MeSH
• zvířata MeSH
• Check Tag
• morčata MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• gibereliny * MeSH

Nitrate, one of the main nitrogen (N) sources for crops, acts as a nutrient and key signaling molecule coordinating gene expression, metabolism, and various growth processes throughout the plant life cycle. It is widely accepted that nitrate-triggered developmental programs cooperate with hormone synthesis and transport to finely adapt plant architecture to N availability. Here, we report that nitrate, acting through its signaling pathway, promotes growth in Arabidopsis and wheat, in part by modulating the accumulation of gibberellin (GA)-regulated DELLA growth repressors. We show that nitrate reduces the abundance of DELLAs by increasing GA contents through activation of GA metabolism gene expression. Consistently, the growth restraint conferred by nitrate deficiency is partially rescued in global-DELLA mutant that lacks all DELLAs. At the cellular level, we show that nitrate enhances both cell proliferation and elongation in a DELLA-dependent and -independent manner, respectively. Our findings establish a connection between nitrate and GA signaling pathways that allow plants to adapt their growth to nitrate availability.

• Klíčová slova
• Arabidopsis, DELLA proteins, gibberellins, growth, hormone biosynthesis, nitrate, plant development, wheat,
• MeSH
• Arabidopsis * metabolismus   MeSH
• dusičnany MeSH
• gibereliny metabolismus   MeSH
• proteiny huseníčku * metabolismus   MeSH
• regulace genové exprese u rostlin MeSH
• regulátory růstu rostlin metabolismus   MeSH
• rostlinné proteiny metabolismus   MeSH
• rostliny genetika   MeSH
• signální transdukce fyziologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• dusičnany MeSH
• gibereliny MeSH
• proteiny huseníčku * MeSH
• regulátory růstu rostlin MeSH
• rostlinné proteiny MeSH

Plants have evolved several strategies to cope with the ever-changing environment. One example of this is given by seed germination, which must occur when environmental conditions are suitable for plant life. In the model system Arabidopsis thaliana seed germination is induced by light; however, in nature, seeds of several plant species can germinate regardless of this stimulus. While the molecular mechanisms underlying light-induced seed germination are well understood, those governing germination in the dark are still vague, mostly due to the lack of suitable model systems. Here, we employ Cardamine hirsuta, a close relative of Arabidopsis, as a powerful model system to uncover the molecular mechanisms underlying light-independent germination. By comparing Cardamine and Arabidopsis, we show that maintenance of the pro-germination hormone gibberellin (GA) levels prompt Cardamine seeds to germinate under both dark and light conditions. Using genetic and molecular biology experiments, we show that the Cardamine DOF transcriptional repressor DOF AFFECTING GERMINATION 1 (ChDAG1), homologous to the Arabidopsis transcription factor DAG1, is involved in this process functioning to mitigate GA levels by negatively regulating GA biosynthetic genes ChGA3OX1 and ChGA3OX2, independently of light conditions. We also demonstrate that this mechanism is likely conserved in other Brassicaceae species capable of germinating in dark conditions, such as Lepidium sativum and Camelina sativa. Our data support Cardamine as a new model system suitable for studying light-independent germination studies. Exploiting this system, we have also resolved a long-standing question about the mechanisms controlling light-independent germination in plants, opening new frontiers for future research.

• Klíčová slova
• Cardamine hirsuta, DOF AFFECTING GERMINATION1, gibberellins, light, seed germination,
• MeSH
• Arabidopsis genetika   metabolismus   MeSH
• Cardamine * genetika   metabolismus   fyziologie   účinky záření   růst a vývoj   MeSH
• gibereliny * metabolismus   MeSH
• klíčení * účinky záření   genetika   fyziologie   MeSH
• proteiny huseníčku metabolismus   genetika   MeSH
• regulace genové exprese u rostlin MeSH
• semena rostlinná * růst a vývoj   genetika   účinky záření   metabolismus   MeSH
• světlo MeSH
• transkripční faktory metabolismus   genetika   MeSH
• zpětná vazba fyziologická MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• gibereliny * MeSH
• proteiny huseníčku MeSH
• transkripční faktory MeSH